Will mark the BRAINLEST If you know any of the answers please help!?! 1.) Bicycles have three types of tires: mountain bike, road touring, and cruising. An experiment is to be conducted to determine whether the mileage before a tire change is needed is the same for all three types of tires. In previous studies, it was determined that bicycle weight (light, normal, heavy) is associated with frequency of tire changes, but bike type (mountain, road, cruising) is not associated with frequency of tire change. How would blocking best be used?
a. By blocking on bicycle type
b. By blocking on mileage
c. Blocking is not suggested.
d. By blocking on tire type
e. By blocking on bicycle weight

2.) From 2010 to 2015, a group of researchers conducted an experiment using two types of pain medication: pill A and pill B. The researchers gave the doctors the pills in unidentified packages so they would not know which package was pill A and which package was pill B. The patients participating did not know which pill they received either. What is this an example of?
a. The effect of a treatment unit
b. The placebo effect
c. A control group study
d. A double-blind study
e. Voluntary response bias

3.) Cocoa plant type 1 yielded 155 bushels per acre last year at a research farm. This year, cocoa plant type 2, planted in the same location, yielded only 123 bushels per acre and there was a major freeze. The researchers do not know whether the difference is the result of the superiority of type 1 or the freeze. What is this an example of?
a. Bias
b. Confounding variable
c. Matched-pairs design
d. The placebo effect
e. Replication

4.) A cell phone company is trying to find a waterproof cell phone case to add to its product line. Company managers know that plastic and silicone will be used. They also know that the depth of the water—less than five feet, between five feet and 20 feet, and more than 20 feet—affects the waterproof case. An experiment will compare all combinations of these choices. The cell phones will be subjected to each treatment, with one group dropped in water without a case, and all phones will be scored for quality. What is the control?
a. Cell phones in the plastic case
b. Cell phones in the silicone case
c. Cell phones in the plastic case dropped in water less than five feet deep
d. Cell phones in the silicone case dropped in water more than 20 feet deep
e. Cell phones with no case

5.) Do children prefer purple juice or yellow juice? Two different supplements, which have no effect on taste, are used on identical juice to produce purple juice or yellow juice. Volunteer children are randomly assigned to either purple juice or yellow juice, and they are asked to rate the juice on a scale from 1 point to 10 points. Is blinding demonstrated in the experiment?
a. No, because the volunteers do not know the color juice they are getting
b. Yes, by having the experimenter in a separate room pick one of the two containers at random and having a juice pulled from that container remotely
c. Yes, by having the statistician analyzing the results not know which volunteer sampled which juice
d. Yes, by having the volunteers wear a blindfold while drinking the juice out of the container, so that they don't know the color juice they are tasting
e. No, because the volunteers know whether they are drinking purple juice or yellow juice